Method of improving copper interconnects of semiconductor devices for bonding

ABSTRACT

An improved wire bond with the bond pads of semiconductor devices and the lead fingers of lead frames or an improved conductor lead of a TAB tape bond with the bond pad of a semiconductor device. More specifically, an improved wire bond wherein the bond pad on a surface of the semiconductor device comprises a layer of copper and at least one layer of metal and/or at least a barrier layer of material between the copper layer and one layer of metal on the copper layer to form a bond pad.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 09/332,665,filed Jun. 14, 1999, now U.S. Pat. No. 6,544,880, issued Apr. 8, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to improved bonding of conductors with thebond pads of semiconductor devices, such as the bonding of wires to thebond pads of semiconductor devices and lead frames associated therewithor the bonding of the conductor leads in TAB tape bonding to the bondpads of semiconductor devices. More specifically, the present inventionrelates to improved bonds with copper bond pads of semiconductordevices, such as wire bonding or improved conductor lead bonding of TABtape to the copper bond pads of semiconductor devices.

2. State of the Art

In semiconductor device manufacture, a single semiconductor die (orchip) is typically mounted within a sealed package. In general, thepackage protects the semiconductor die from damage and from contaminantsin the surrounding environment. In addition, the package provides asubstantial lead system for connecting the electrical devices formed onthe die to a printed circuit board or any other desired suitableexternal circuitry.

Each semiconductor die comprises a substrate having a lower surface(commonly referred to as the back of the die) that is devoid ofcircuitry and an upper surface (commonly referred to as the activesurface or face of the die) having integrated circuitry constructedthereon. The integrated circuitry is electrically accessible via bondpads located on the active surface of the semiconductor die which may bearranged in a wide variety of patterns, such as around the periphery ofthe semiconductor die, the center of the semiconductor die, or both,etc.

One of the problems associated with the decreasing size of thesemiconductor die and the increasing amount of circuitry included in thesemiconductor die is the need to, at least, maintain the speed at whichthe semiconductor die operates and, if possible, to increase theoperating speed of the semiconductor die. Since aluminum is typicallyused as the material for the connecting circuits of the semiconductordie with smaller circuit line widths of aluminum, it is difficult tomaintain or increase the speed of the semiconductor die. Further, it isnecessary to connect an ever-increasing number of bond pads on theactive surface of the semiconductor die with an ever-increasing numberof lead fingers of the lead frame or other type conductors, such as theconductor leads of TAB tape. In each instance, the use of a moreconductive material for the connecting circuits of the semiconductor dieconnecting to the bond pads on the active surface of the semiconductordie is required.

In an effort to increase the operating speeds of semiconductor diceusing small width circuit lines, improved techniques and processes havebeen developed to substitute the metal copper for aluminum in thecircuit lines of the semiconductor die. However, the use of copper forcircuit lines and bond pads of the semiconductor die causes problemswhen wire bonds are used to connect the copper bond pads of thesemiconductor die to the leads of a lead frame or the lead conductors ofTAB tape. It is difficult to form wire bond connections using standardor conventional wire bonding equipment when forming wire bonds toconnect the copper bond pads of a semiconductor die to the leads of alead frame.

Typically, the initial component in the packaging process is a leadframe. The lead frame is a metal frame which supports the semiconductordie for packaging and provides the leads for the final semiconductorpackage. A typical lead frame strip is produced from metal sheet stock(usually a copper, copper alloy, alloy 42, etc.) and is adapted to mountthe semiconductor die.

A conventional lead frame has the semiconductor die adhesively mountedon a die paddle of the lead frame while the lead fingers (leads) extendaround the periphery of the semiconductor die (the edges) terminatingadjacent thereto. Subsequently, wire bonds are made to connect the bondpads on the active surface of the semiconductor die to the appropriatelead finger of the lead frame. After the wire bonding operation, thelead frame and semiconductor die are encapsulated in a transfer diemolding process. After encapsulation, the lead frame is trimmed with theremainder of the individual lead fingers being formed into the desiredpackaging configuration.

One of the problems associated with conventional lead frameconfigurations is that with the decreasing size of the semiconductor dieand the increasing amount of circuitry included in the semiconductordie, it is necessary to connect an ever-increasing number of bond padson the active surface of the semiconductor die with an ever-increasingnumber of lead fingers of the lead frame. This requires that the bondpads on the semiconductor die be located on smaller pitch spacings andthe width of the lead fingers be smaller. This, in turn, leads tosmaller wire bonds on both the bond pads of the semiconductor die andthe lead fingers of the lead frame, which causes the wire bonds to bemore highly stressed by the forces placed on them. This stress placed onthe wire bonds requires that the metal of the bond pad, to which thewire bond is to be made, be highly susceptible to wire bonding and theformation of high strength wire bonds therewith when using well-knownwire material, such as gold, etc. and standard or conventional wirebonding equipment.

In a Leads-Over-Chip (LOC) type lead frame configuration for anintegrated circuit semiconductor device, the lead fingers of the leadframe extend over the active surface of the semiconductor die beinginsulated therefrom by tape which is adhesively bonded to the activesurface of the semiconductor die and the bottom of the lead fingers. Inthis manner, the semiconductor die is supported directly from the leadfingers of the lead frame. Electrical connections are made between thelead fingers of the lead frame and the bond pads on the active surfaceof the semiconductor die by way of wire bonds extending therebetween.After wire bonding, the lead frame and semiconductor die areencapsulated in suitable plastic material. Subsequently, the leadfingers are trimmed and formed to the desired configuration to completethe packaged semiconductor device assembly.

One of the shortcomings of the prior art LOC semiconductor dieassemblies is that the tape used to bond to the lead fingers of the leadframe does not adequately lock the lead fingers in position for the wirebonding process. At times, the adhesive on the tape is not strong enoughto fix or lock the lead fingers in position for wire bonding as the leadfingers pull away from the tape before wire bonding. Alternately, thelead fingers will pull away from the tape after wire bonding of thesemiconductor die but before encapsulation of the semiconductor die andlead frame either causing shorts between adjacent wire bonds or causingthe wire bonds to pull loose from either the bond pads of thesemiconductor die or lead finger of the lead frame. As before withconventional lead frames, with the decreasing size of the semiconductordie and the increasing amount of circuitry included in the semiconductordie, it is necessary to connect an ever-increasing number of bond padson the active surface of the semiconductor die with an ever-increasingnumber of lead fingers of the lead frame. This requires that the bondpads on the semiconductor die be located on smaller pitch spacings andthe width of the lead fingers be smaller. This, in turn, leads tosmaller wire bonds on both the bond pads and the lead fingers of thelead frame, which cause the wire bonds to be more highly stressed by theforces placed on them.

Therefore, when using copper as the metal for the formation of circuitsand bond pads of a semiconductor die, a need exists forincreased-strength wire bonds between the lead fingers of a lead frameand the bond pads of a semiconductor die or between the conductor leadsof TAB tape and the bond pads of a semiconductor die, particularly, asthe size of the semiconductor die, the size of the bond pads thereon,the size of the lead fingers connected by wire bonds to bond pads, andthe pitch thereof, all decrease.

It is known in the art to form bumps on the bond pads of a semiconductordie using wire bonding apparatus for subsequent wire bond Tape AutomatedBonding (TAB) or flip-chip (face-down) assembly of a bare chip die to asubstrate. Such is illustrated in U.S. Pat. Nos. 4,750,666 and5,058,798. It is also known to repair defective or broken wire bonds tobond pads of a semiconductor die by forming a flattened pad over theremaining portion of the wire and, subsequently, bonding the end ofanother wire thereover. Such is illustrated in U.S. Pat. No. 5,550,083.Other types of wire bonding operations on the bond pads of asemiconductor die are illustrated in U.S. Pat. Nos. 5,235,212,5,298,793, 5,343,064, 5,371,654, and 5,492,863. However, such patentsuse aluminum for the circuits and bond pads of the semiconductor dierather than copper, which is difficult to make effective bonds theretousing conventional processes and equipment.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to improved wire bonds with the bond padsof semiconductor devices and either the lead fingers of lead frames orthe conductor leads of TAB tape. More specifically, the presentinvention relates to improved wire bonds and improved conductor leadbonds of TAB tape to the bond pads of a semiconductor device wherein thebond pads comprise a copper layer and at least one layer of metalcovering a portion of the copper layer.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, which illustrate what is currently considered to be thebest mode for carrying out the invention:

FIG. 1 is a cross-sectional view of a portion of a semiconductor diehaving a plurality of copper bond pads thereon having one or more layersof metal thereon;

FIGS. 2A through 2F are views of a portion of a semiconductor devicehaving a bond pad of the present invention located thereon having a wirebond formed thereon;

FIGS. 3A through 3C are views of a portion of a semiconductor deviceillustrating the formation of a bond pad thereon of the presentinvention having a wire bond formed thereon;

FIGS. 4A through 4D are views of a portion of a semiconductor devicehaving a bond pad of the present invention located thereon with aconductor lead of a TAB tape bonded thereto; and

FIGS. 5A through 5J are drawings illustrating processes of forming abond pad of the present invention on a semiconductor device and asubsequent wire bond and bonding of a conductor lead of a TAB tapetherewith.

The present invention will be better understood when the drawings aretaken in conjunction with the following description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to drawing FIG. 1, a portion of a semiconductor device 10 isillustrated having a plurality of bond pads 12 located on the activesurface 14 of a semiconductor device 10 having a layer of insulatingmaterial 13, and a passivation layer, thereon. The semiconductor device10 may be of any desired type having any desired configuration of bondpads 12 connected to the active circuitry therein. As illustrated, bondpads 12 include a copper metal layer base 12′ and one or more additionalmetal layers 12″ thereon to facilitate the formation of an acceptablewire bond using well-known alloys of metal for the wire to the bond pads12. The wire bond may be formed or secured to the bond pads 12 by anydesired, well-known, wire bonding apparatus used in the industry usingany desired type of wire, such as aluminum, copper, copper alloy,aluminum-copper alloy, gold, silver, gold-silver alloy, platinum, etc.,although gold wire is preferred to be used as gold does not form anoxide after the deposition thereof on the bond pad 12 as would aluminum,silver, etc.

As necessary, the bond pad 12 may be comprised of layers of differentmetals to enhance bonding characteristics. For instance, layer 12′ is ofcopper metal such as is used for the circuits of the semiconductordevice 10, i.e., copper metal, a copper alloy, etc. Typically, the layer12″ would be of gold, gold alloy, silver, silver alloy, palladium andalloys thereof, noble metals and alloys thereof, nickel and alloysthereof, nickel and gold alloys, zincated copper, etc. The layer 12″ mayfurther include an additional intermediate layer of metal or othermaterials to help prevent intermetallic compounds from forming betweenthe copper layer 12′ and layer 12″ and/or for adhesion purposes. Forinstance, the layer 12″ may commonly comprise a layer of TaN, TiN, Nialloys, etc. If a gold wire is used for wire bonding, the metal layer12″ may typically be a gold or gold alloy metal layer. In this manner,by forming the bond pad 12 of multiple layers of metal, a strong bondbetween the wire used for wire bonding and the copper metal layer 12′ ofthe bond pad 12 may be formed, particularly since gold does not form anoxide coating after the deposition thereof to affect any subsequent bondof material thereto. If desired, one layer of the metal layer 12″ ofmultiple metal layers 12″ may be a layer of metal forming a barrier toprevent any copper from the layer 12′ from migrating therethrough or anymetal of the metal layer 12″ from migrating to the copper layer 12′.Additionally, one layer of the metal layer 12″ may be a layer of metalfor adhesion promoting purposes to either the copper layer 12′ or themetal layer 12″.

Referring to drawing FIGS. 2A through 2C, a process for formingmulti-layer bond pads 12 on the active surface 14 of substrate 11 isillustrated. A portion of a semiconductor device 10 is shown in drawingFIG. 2A having a copper layer 12′ forming a portion of the bond pad 12.Illustrated in drawing FIG. 2B, is a layer of metal 12″ overlying thecopper layer 12′ of the bond pad 12. The layer of metal 12″ may beselectively plated by well-known techniques over the copper layer 12′,the layer of metal 12″ having good properties for the wire bonding of awire 20 to the bond pad 12. Illustrated in drawing FIG. 2C, a wire 20 isbonded by well-known wire bonding apparatus to the layer of metal 12″ ofthe bond pad 12 using a wire bond ball 22.

Still referring to drawing FIGS. 2A through 2C, a portion of asemiconductor device 10 is shown having a bond pad 12 thereon with thecopper layer 12′ located thereon having the upper surface thereoflocated at approximately the same level as the active surface 14 ofsubstrate 11 of the device 10, the active surface 14 having a layer ofinsulation 13 (typically a passivation layer of an insulating oxide orinsulating nitride) thereon. As illustrated in drawing FIG. 2B, thecopper layer 12′ of bond pad 12 has a suitable metal layer 12″selectively plated thereon using well-known plating processes, thefunction of the metal layer 12″ being to provide a good metal to whichan effective wire bond may be formed using well-known wire bondingapparatus.

Illustrated in drawing FIG. 2C, a wire 20 is wire bonded to metal layer12″ using a ball 22 formed on the end of the wire 20 using anywell-known suitable wire bonding apparatus. In the wire bonding process,the portion of the metal layer 12″ on the bond pad 12 located under ball22 of the wire 20 of the wire bond thereto may be consumed during thewire bonding process, thereby allowing the ball 22 of the wire 20 of thewire bond to make direct contact with the copper layer 12′ of the bondpad 12. For example, when the metal layer 12″ is gold and the ball 22 ofwire 20 is gold wire, the metal layer 12″ located under the ball 22 willbecome part of the ball 22 during the wire bonding process with the ball22 being bonded to the copper layer 12′ of the bond pad 12.

Referring to drawing FIG. 2D, a wire 20 is wire bonded to copper layer12′ with the ball 22 on the end of wire 20 consuming or adding part ofthe metal layer 12″ during the bonding process forming the ball 22 onthe end of wire 20 connecting the wire 20 to the copper layer 12′.

Referring to drawing FIG. 2E, a portion of a semiconductor device 10 isshown having a bond pad 12 thereon with the copper layer 12′ locatedthereon having the upper surface thereof located at approximately thesame level as the active surface 14 of substrate 11 of the device 10,the active surface 14 having a layer of insulation 13 (typically apassivation layer of an insulating oxide or insulating nitride) thereon.As illustrated in drawing FIG. 2E, the copper layer 12′ of bond pad 12has a barrier layer 12′″ formed of a suitable material having a suitablemetal layer 12″ selectively plated thereon using well-known platingprocesses. The function of the barrier layer 12′″ is to help preventinteraction between the copper layer 12′ and the suitable metal layer12″ of the bond pad 12 and/or to help prevent or decrease the growth ofintermetallics between the copper layer 12′ and the metal layer 12″. Forinstance, barrier materials, such as titanium, tungsten, tantalum,nickel, tantalum-nickel alloys, titanium-nickel alloys,titanium-tungsten alloys, etc. are frequently used in conjunction withaluminum alloy interconnects. In other instances, a barrier layer ofnickel between copper and tin will decrease the growth of tin-copperintermetallics. The layers of metal forming the bond pads 12 alsooccasionally are silicided, or have a refractory interconnect material,such as molybdenum, tungsten, or tungsten silicide, as part thereof. Thefunction of the metal layer 12″ is to provide a good metal to which aneffective wire bond may be formed using well-known wire bondingapparatus, such as a metal layer 12″ of gold when gold wire 20 is beingused for wire bonding.

Referring to drawing FIG. 2F, a wire 20 is wired bonded to barrier layer12′″ with the ball 22 on the end of wire 20 consuming part of the metallayer 12″ during the bonding process forming the ball 22 on the end ofwire 20 connecting the wire 20 to the barrier layer 12′″.

Referring to drawing FIGS. 3A through 3C, a portion of a semiconductordevice 10 is shown wherein a layer of copper 12′ is deposited on thesubstrate 11 using any desired well-known process having a thin layer ofmetal 12″, as described hereinbefore, deposited thereon. The thin layerof metal 12″ may be deposited on the copper layer 12′ by any well-knownprocess, such as sputter deposition, electrodeposition, electrolessdeposition, etc.

Referring to drawing FIG. 3B, the portion of the semiconductor device 10is shown after the copper layer 12′ and layer of metal 12″ depositedthereon have been patterned using well-known techniques to apply aphotoresist in a desired pattern with the subsequent etching of thecopper layer 12′ and layer of metal 12″ to form a bond pad 12 on thesubstrate 11 of the semiconductor device 10. The copper layer 12′ andlayer of metal 12″ deposited thereon may be any desired shape, size, andnumber for the desired number of bond pads 12 on the substrate 11.Further, the copper layer 12′ may include at least two or more layers ofmetal with the upper layer being a copper layer, thereby forming a stackof layers of differing metal with the upper layer being a copper layer.

Referring to drawing FIG. 3C, a portion of the semiconductor device 10is shown having a wire 20 bonded to the layer of metal 12″ of the bondpad 12 using a ball 22 type bond thereto for wire bonding using anydesired well-known wire bonding apparatus. The semiconductor substrate11 includes a layer of insulating material 13, as describedhereinbefore, on active surface 14 thereof surrounding the bond pad 12.

Referring to drawing FIGS. 4A through 4D, in drawing FIG. 4A, a portionof a semiconductor device 10 is shown having a bond pad 12 thereon withthe copper layer 12′ located thereon having the upper surface thereoflocated at approximately the same level as the active surface 14 ofsubstrate 11 of the device 10, the active surface 14 having a layer ofinsulation 13 (typically a passivation layer of an insulating oxide orinsulating nitride) thereon. Also illustrated in drawing FIG. 4A, thecopper layer 12′ of bond pad 12 has a suitable metal layer 12″selectively plated thereon using well-known plating processes. Thefunction of the metal layer 12″ is to provide a good metal to which aneffective wire bond may be formed using well-known wire bondingapparatus.

Illustrated in drawing FIG. 4B, the copper layer 12′ of bond pad 12 hasa suitable barrier layer 12′″ located between the copper layer 12′ andthe suitable metal layer 12″, such as described hereinbefore.

Referring to drawing FIG. 4C, a portion of a semiconductor device 10 isshown having a bond pad 12 thereon having a copper layer 12′ locatedthereon having a portion bonded thereto of a conductor lead 23 locatedon a portion of a substrate 24 of a portion of a TAB tape 21. Thesurface 14 of substrate 11 of the semiconductor device 10 has a layer ofinsulation 13 (typically a passivation layer of an insulating oxide orinsulating nitride) thereon. Also illustrated in drawing FIG. 4C, thefunction of the metal layer 12″ is to provide a good metal to which aneffective bond may be formed using well-known bonding apparatus to bondthe conductor lead 23 of the TAB tape 21. The conductor lead 23 of theTAB tape 21 may be of any suitable metal, such as copper, copper alloys,etc. The metal layer 12″ may be of any suitable metal, such as describedherein.

Referring to drawing FIG. 4D, a portion of a semiconductor device 10 isshown having a bond pad 12 thereon having a copper layer 12′ locatedthereon having a barrier layer 12′″ located thereon having, in turn, ametal layer 12″ located thereon. The metal layer 12″ of the bond pad 12is bonded to a portion of a conductor lead 23 located on a portion of asubstrate 24 of a portion of a TAB tape 21. The conductor lead 23 of theportion of the TAB tape 21 including a layer 26 of suitable metallocated thereon for the bonding of the conductor lead 23 to the metallayer 12″ of the bond pad 12 of the semiconductor device 10. The surface14 of substrate 11 of the semiconductor device 10 has a layer ofinsulation 13 (typically a passivation layer of an insulating oxide orinsulating nitride) thereon. Also illustrated in drawing FIG. 4D, thefunction of the metal layer 12″ is to provide a good metal to which aneffective bond may be formed using well-known bonding apparatus to themetal layer 26 of the conductor lead 23 of the TAB tape 21. Thesubstrate 24 and metal layer 26 may be of any suitable metal for bondingpurposes, such as gold, alloys of gold, etc. The conductor lead 23 ofthe TAB tape 21 may be of any suitable metal, such as copper, copperalloys, etc. The metal layer 12″ may be of any suitable metal, such asdescribed herein. The barrier layer 12′″ may be of any suitable metal ormaterial, such as described herein.

Referring to drawing FIGS. 5A through 5J, various differing processesfor the formation of the bond pad 12 including a copper layer 12′ and alayer of metal 12″ and, if desired, a barrier layer 12′″ areillustrated.

Referring to drawing FIG. 5A, a process 100 for the formation of a bondpad 12 including a copper layer 12′ and a layer of metal 12″ thereon forwire bonding purposes as described hereinbefore is illustrated. Asillustrated in step 102, a substrate 11 as described hereinbefore for asemiconductor device 10 has a layer of copper or copper alloy 12′deposited thereon using any desired deposition process. Subsequently, instep 104, a layer of metal 12″ is deposited on the copper layer 12′using any well-known deposition process. Then, in step 106, the copperlayer 12′ and layer of metal 12″ is patterned and etched to form thedesired shape, number, and pattern for the bond pads 12 on the activesurface 14 of the substrate 11 of the semiconductor device 10. A layerof insulation 13 is typically applied to the active surface 14 of thesubstrate 11 to protect the circuitry formed thereon of thesemiconductor device 10. After the completion of the semiconductordevice 10 having bond pads 12 including a copper layer 12′ and layer ofmetal 12″ thereon, the semiconductor device may be assembled to a leadframe (not shown) for wire bonding a wire 20 to the bond pad 12 of thesemiconductor device 10 using any suitable wire bonding process 108 andapparatus.

Referring to drawing FIG. 5B, a process 200 for the formation of a bondpad 12 including a copper layer 12′ and a layer of metal 12″ thereon forwire bonding purposes as described hereinbefore is illustrated. Asillustrated in step 202, a substrate 11 as described hereinbefore for asemiconductor device 10 has a layer of copper or copper alloy 12′deposited thereon using any desired deposition process. Subsequently, instep 204, the copper layer 12″ is patterned and etched to form thedesired shape, number, and pattern for the bond pads 12 on the activesurface 14 of the substrate 11 of the semiconductor device 10. Then, instep 206, the layer of metal 12″ is deposited on the copper layer 12′using any desired deposition process, as described hereinbefore, such aselectrodeposition, electroless deposition, etc. to form the bond pad 12having a copper layer 12′ and layer of metal 12″ thereon for good wirebonding properties. A layer of insulation 13 is typically applied to theactive surface 14 of the substrate 11 to protect the circuitry formedthereon of the semiconductor device 10. After the completion of thesemiconductor device 10 having bond pads 12 including a copper layer 12′and layer of metal 12″ thereon, the semiconductor device may beassembled to a lead frame (not shown) for wire bonding a wire 20 to thebond pad 12 of the semiconductor device 10 using any suitable wirebonding process 208 and apparatus.

Referring to drawing FIG. 5C, a process 300 for the formation of a bondpad 12 including a copper layer 12′, a barrier layer 12′″, and a layerof metal 12″ thereon for wire bonding purposes as described hereinbeforeis illustrated. As illustrated in step 302, a substrate 11 as describedhereinbefore for a semiconductor device 10 has a layer of copper orcopper alloy 12′ deposited thereon using any desired deposition process.Subsequently, in step 304, a barrier layer 12′″ of suitable material isdeposited on the copper layer 12′ using any well-known depositionprocess. Then, in step 306, the copper layer 12′ and barrier layer 12′″are patterned and etched to form the desired shape, number, and patternfor the bond pads 12 on the active surface 14 of the substrate 11 of thesemiconductor device 10. Then a metal layer 12″ is deposited in step 308over the barrier layer 12′″ and subsequently patterned in step 310. Alayer of insulation 13 is typically applied to the active surface 14 ofthe substrate 11 to protect the circuitry formed thereon of thesemiconductor device 10. After the completion of the semiconductordevice 10 having bond pads 12 including a copper layer 12′, barrierlayer 12′″, and layer of metal 12″ thereon, the semiconductor device maybe assembled to a lead frame (not shown) for wire bonding a wire 20 tothe bond pad 12 of the semiconductor device 10 using any suitable wirebonding process 312 and apparatus.

Referring to drawing FIG. 5D, a process 400 for the formation of a bondpad 12 including a copper layer 12′, a barrier layer 12′″, and a layerof metal 12″ thereon for wire bonding purposes as described hereinbeforeis illustrated. As illustrated in step 402, a substrate 11 as describedhereinbefore for a semiconductor device 10 has a layer of copper orcopper alloy 12′ deposited thereon using any desired deposition process.Subsequently, in step 404, a barrier layer 12′″ of suitable material isdeposited on the copper layer 12′ using any well-known depositionprocess. Then, in step 406, a metal layer 12″ is deposited on thebarrier layer 12′″. In step 408, the copper layer 12′, barrier layer12′″, and metal layer 12″ are patterned and etched to form the desiredshape, number, and pattern for the bond pads 12 on the active surface 14of the substrate 11 of the semiconductor device 10. A layer ofinsulation 13 is typically applied to the active surface 14 of thesubstrate 11 to protect the circuitry formed thereon of thesemiconductor device 10. After the completion of the semiconductordevice 10 having bond pads 12 including a copper layer 12′, barrierlayer 12′″, and layer of metal 12″ thereon, the semiconductor device maybe assembled to a lead frame (not shown) for wire bonding a wire 20 tothe bond pad 12 of the semiconductor device 10 using any suitable wirebonding process 410 and apparatus.

Referring to drawing FIG. 5E, a process 500 for the formation of a bondpad 12 including a copper layer 12′ and a layer of metal 12″ thereon forwire bonding purposes as described hereinbefore is illustrated. Asillustrated in step 502, a substrate 11 as described hereinbefore for asemiconductor device 10 has a layer of copper or copper alloy 12′deposited thereon using any desired deposition process. Subsequently, instep 504, at least two barrier layers 12′″ are deposited on the copperlayer. In step 506, a metal layer 12″ is deposited on the barrier layer12′″ using any desired deposition process, as described hereinbefore,such as electrodeposition, electroless deposition, etc. In step 508, thecopper layer 12′, barrier layer 12′″, and metal layer 12″ are patternedto form the bond pad 12 having a copper layer 12′, barrier layer 12′″,and layer of metal 12″ thereon for good wire bonding properties. A layerof insulation 13 is typically applied to the active surface 14 of thesubstrate 11 to protect the circuitry formed thereon of thesemiconductor device 10. After the completion of the semiconductordevice 10 having bond pads 12 including a copper layer 12′, at least twobarrier layers 12′″, and layer of metal 12″ thereon, the semiconductordevice may be assembled to a lead frame (not shown) for wire bonding awire 20 to the bond pad 12 of the semiconductor device 10 using anysuitable wire bonding process 510 and apparatus.

Referring to drawing FIGS. 5F through 5J, the processes set forththerein are similar to those described regarding those illustrated indrawing FIGS. 5A through 5E, except that a conductor lead 23 of a TABtape 21 is bonded to the bond pad 12 of the semiconductor device 10,rather than a wire bond being made to the bond pad 12 of a semiconductordevice 10.

Referring to drawing FIG. 5F, a process 600 for the formation of a bondpad 12 including a copper layer 12′ and a layer of metal 12″ thereon forconductor lead 23 of TAB tape 21 bonding purposes as describedhereinbefore is illustrated. As illustrated in step 602, a substrate 11as described hereinbefore for a semiconductor device 10 has a layer ofcopper or copper alloy 12′ deposited thereon using any desireddeposition process. Subsequently, in step 604, a layer of metal 12″ isdeposited on the copper layer 12′ using any well-known depositionprocess. Then, in step 606, the copper layer 12′ and layer of metal 12″are patterned and etched to form the desired shape, number, and patternfor the bond pads 12 on the active surface 14 of the substrate 11 of thesemiconductor device 10. A layer of insulation 13 is typically appliedto the active surface 14 of the substrate 11 to protect the circuitryformed thereon of the semiconductor device 10. After the completion ofthe semiconductor device 10 having bond pads 12 including a copper layer12′ and layer of metal 12″ thereon, the semiconductor device may beassembled to a conductor lead 23 of a TAB tape 21 for bonding aconductor lead 23 to the bond pad 12 of the semiconductor device 10using any suitable bonding process 608 and apparatus.

Referring to drawing FIG. 5G, a process 700 for the formation of a bondpad 12 including a copper layer 12′ and a layer of metal 12″ thereon forconductor lead 23 of TAB tape 21 bonding purposes as describedhereinbefore is illustrated. As illustrated in step 702, a substrate 11as described hereinbefore for a semiconductor device 10 has a layer ofcopper or copper alloy 12′ deposited thereon using any desireddeposition process. Subsequently, in step 704, the copper layer 12′ ispatterned and etched to form the desired shape, number, and pattern forthe bond pads 12 on the active surface 14 of the substrate 11 of thesemiconductor device 10. Then, in step 706, the layer of metal 12″ isdeposited on the copper layer 12′ using any desired deposition process,as described hereinbefore, such as electrodeposition, electrolessdeposition, etc. to form the bond pad 12 having a copper layer 12′ andlayer of metal 12″ thereon for good wire bonding properties. A layer ofinsulation 13 is typically applied to the active surface 14 of thesubstrate 11 to protect the circuitry formed thereon of thesemiconductor device 10. After the completion of the semiconductordevice 10 having bond pads 12 including a copper layer 12′ and layer ofmetal 12″ thereon, the semiconductor device may be assembled to aconductor lead 23 of a TAB tape 21 for wire bonding a conductor lead 23to the bond pad 12 of the semiconductor device 10 using any suitablebonding process 708 and apparatus.

Referring to drawing FIG. 5H, a process 800 for the formation of a bondpad 12 including a copper layer 12′, a barrier layer 12′″, and a layerof metal 12″ thereon for conductor lead 23 of TAB tape 21 bondingpurposes as described hereinbefore is illustrated. As illustrated instep 802, a substrate 11 as described hereinbefore for a semiconductordevice 10 has a layer of copper or copper alloy 12′ deposited thereonusing any desired deposition process. Subsequently, in step 804, abarrier layer 12′″ of suitable material is deposited on the copper layer12′ using any well-known deposition process. Then, in step 806, thecopper layer 12′ and barrier layer 12′″ are patterned and etched to formthe desired shape, number, and pattern for the bond pads 12 on theactive surface 14 of the substrate 11 of the semiconductor device 10.Then a metal layer 12″ is deposited in step 808 over the barrier layer12′″ and subsequently patterned in step 810. A layer of insulation 13 istypically applied to the active surface 14 of the substrate 11 toprotect the circuitry formed thereon of the semiconductor device 10.After the completion of the semiconductor device 10 having bond pads 12including a copper layer 12′, barrier layer 12′″, and layer of metal 12″thereon, the semiconductor device may be assembled to a conductor lead23 of a TAB tape 21 for bonding a conductor lead 23 to the bond pad 12of the semiconductor device 10 using any suitable bonding process 812and apparatus.

Referring to drawing FIG. 5I, a process 900 for the formation of a bondpad 12 including a copper layer 12′, a barrier layer 12′″, and a layerof metal 12″ thereon for conductor lead 23 of TAB tape 21 bondingpurposes as described hereinbefore is illustrated. As illustrated instep 902, a substrate 11 as described hereinbefore for a semiconductordevice 10 has a layer of copper or copper alloy 12′ deposited thereonusing any desired deposition process. Subsequently, in step 904, abarrier layer 12′″ of suitable material is deposited on the copper layer12′ using any well-known deposition process. Then, in step 906, a metallayer 12″ is deposited on the barrier layer 12′″. In step 908, thecopper layer 12′, barrier layer 12′″, and metal layer 12″ are patternedand etched to form the desired shape, number, and pattern for the bondpads 12 on the active surface 14 of the substrate 11 of thesemiconductor device 10. A layer of insulation 13 is typically appliedto the active surface 14 of the substrate 11 to protect the circuitryformed thereon of the semiconductor device 10. After the completion ofthe semiconductor device 10 having bond pads 12 including a copper layer12′, barrier layer 12′″, and layer of metal 12″ thereon, thesemiconductor device may be assembled to a conductor lead 23 of a TABtape 21 for bonding a conductor lead 23 to the bond pad 12 of thesemiconductor device 10 using any suitable bonding process 910 andapparatus.

Referring to drawing FIG. 5J, a process 1000 for the formation of a bondpad 12 including a copper layer 12′ and a layer of metal 12″ thereon forconductor lead 23 of TAB tape 21 bonding purposes as describedhereinbefore is illustrated. As illustrated in step 1002, a substrate 11as described hereinbefore for a semiconductor device 10 has a layer ofcopper or copper alloy 12′ deposited thereon using any desireddeposition process. Subsequently, in step 1004, at least two barrierlayers 12′″ are deposited on the copper layer. In step 1006, a metallayer 12″ is deposited on the barrier layer 12′″ using any desireddeposition process, as described hereinbefore, such aselectrodeposition, electroless deposition, etc. In step 1008, the copperlayer 12′, barrier layers 12′″, and metal layer 12″ are patterned toform the bond pad 12 having a copper layer 12′, barrier layers 12′″, andlayer of metal 12″ thereon for good wire bonding properties. A layer ofinsulation 13 is typically applied to the active surface 14 of thesubstrate 11 to protect the circuitry formed thereon of thesemiconductor device 10. After the completion of the semiconductordevice 10 having bond pads 12 including a copper layer 12′, barrierlayer 12′″, and layer of metal 12″ thereon, the semiconductor device maybe assembled to a conductor lead 23 of a TAB tape 21 for wire bonding aconductor lead 23 to the bond pad 12 of the semiconductor device 10using any suitable bonding process 1010 and apparatus.

It will be understood that changes, additions, deletions, andmodifications may be made to the present invention which are intended tobe within the scope of the claimed invention, such as the use of morethan a single layer of metal over the copper layer to form a bond pad,the copper layer being multiple layers of differing materials, thebarrier layer being multiple layers of differing materials, the metallayer being multiple layers of differing materials, etc.

What is claimed is:
 1. A method of forming a semiconductor deviceassembly, said method comprising: providing a substrate having an uppersurface and a lower surface; depositing a layer of copper on a portionof the upper surface and the lower surface of the substrate in contacttherewith; and depositing at least one layer of metal on at least aportion of the layer of copper forming at least one bond pad having atleast one layer of metal thereon on one surface of the upper surface andthe lower surface of the substrate.
 2. The method of claim 1, furthercomprising: connecting one end of a wire to the at least one layer ofmetal using a wire bond.
 3. The method of claim 1, wherein the at leastone layer of metal comprises at least a layer of one of silver metal,gold metal, a silver alloy metal, a gold alloy metal, a silver and goldalloy metal, palladium metal, a noble metal alloy, a nickel metal, and anickel metal alloy.
 4. The method of claim 1, further comprising:depositing at least one other layer of metal on a portion of the atleast one layer of metal.
 5. The method of claim 4, wherein the at leastone layer of metal and the at least one other layer of metal comprises asilver metal alloy and a nickel metal alloy, a nickel metal alloy and asilver metal alloy, a silver metal and a nickel metal, and nickel metaland a silver metal.
 6. The method of claim 1, wherein the copper layercomprises a zincated copper layer.
 7. The method of claim 4, wherein theat least one layer of metal comprises a barrier layer of metal and theat least one other layer of metal comprises an adhesion promoting layerof metal for wire bonding thereto.
 8. The method of claim 1, furthercomprising: depositing an insulative coating on a portion of the onesurface of the upper surface and the lower surface of the substrate. 9.A method of forming a semiconductor device assembly having a substratehaving an upper surface and a lower surface, said method comprising:depositing a layer of copper on a portion of the upper surface and thelower surface of the substrate in contact therewith; and depositing atleast one layer of metal on at least a portion of the layer of copperforming at least one bond pad having at least one layer of metalthereon.
 10. The method of claim 9, further comprising: connecting oneend of a wire to the at least one layer of metal using a wire bond. 11.The method of claim 9, wherein the at least one layer of metal comprisesone of silver metal, gold metal, a silver alloy metal, a gold alloymetal, a silver and gold alloy metal, palladium metal, a noble metal, anoble metal alloy, nickel metal, and a nickel metal alloy.
 12. Themethod of claim 9, further comprising: depositing at least one otherlayer of metal on a portion of the at least one layer of metal.
 13. Themethod of claim 12, wherein the at least one layer of metal and the atleast one other layer of metal comprise one of a silver metal alloy anda nickel metal alloy, a nickel metal alloy and a silver metal alloy, asilver metal and a nickel metal, and nickel metal and a silver metal.14. The method of claim 9, wherein the copper layer comprises a zincatedcopper layer.
 15. The method of claim 2, wherein the at least one layerof metal comprises a barrier layer of metal and the at least one otherlayer of metal comprises an adhesion promoting layer of metal for wirebonding thereto.
 16. The method of claim 9, further comprising:depositing an insulative coating on a portion of the one surface and thelower surface of the substrate.
 17. A method of forming a semiconductordevice assembly having a substrate having an upper surface and a lowersurface, said method comprising: depositing a layer of copper on aportion of the upper surface and the lower surface of the substrate incontact therewith; depositing a barrier layer on at least a portion ofthe layer of copper; and depositing at least one layer of metal on atleast a portion of the barrier layer forming at least one bond padhaving at least one layer of metal thereon on one surface of the uppersurface and the lower surface of the substrate.
 18. The method of claim17, further comprising: connecting one end of a wire to the at least onelayer of metal using a wire bond.